In an offshore drilling operation, a drillstring extends from the rig platform into a wellbore whereat its drillbit drills deeper and deeper into the sea floor. During drilling, pumps circulate mud through the drillbit and back through the riser surrounding the drillstring. Mudpumps are usually large positive displacement pumps which generate flow by reciprocal plunger movement. In a triplex mudpump, for example, three plungers can be reciprocally driven by pony rods to suction the working fluid (e.g., mud slurry) through an inlet and discharge it through an outlet. A typical triplex mudpump could have a horsepower rating from 275 to 2000 BHP and discharge pressures from 1000 psi to 7500 psi. In offshore drilling, as well as many other industrial situations, convenient accessibility of expendable parts, such as reciprocating-rod seals, can be of the utmost importance.